LAUSR

As the main carrier of groundwater in nature, water transport behavior in fracture networks and identification of its main control factors are challenging problems in hydrogeology. Laboratory experiments are designed in this paper using fracture networks made of Perspex plate for a series of hydraulic tests. Using the conditions of different types of connections for inlet and outlet, temperature tracing tests are conducted for determining dominant flow paths. The flow resistances are calculated at different points, and the control factors of the dominant flow paths are then discussed. Three major conclusions are obtained: (1) the existence of the dominant flow phenomenon in fracture networks is verified; (2) the dominant flow paths can be ascertained by monitoring the temperature variation of hot water in complex fracture networks; (3) the flow resistance is the most fundamental reason for forming dominant flow: the channel with less resistance is selected as the dominant path.